Means for measuring conditions in deep wells



P. W. MARTIN MEANS FOR MEASURING CONDITIONS 1N DEEP WELLS Aug. 19, 1952 Filed April 14, 1947 Aug. 19, 1952 P. w. MARTIN 2,607,220

MEANS FOR 'lvlEAsURINGY CONDITIONS IN DEEP WELLS Filed April 14, 1947 5 SheGts-Sheet 2 ATTO R N EY 5 Sheets-Sheet 3 P. w. MARTIN MEANS FOR MEASURING CONDITIONS IN DEEP WELLS Aug. 19, 1952 Filed April 14. 1947 INVENToR. PHILIP w. MARTlN v/sfrToRNEY Aug. 19, 1952 P. w. MARTIN MEANS FOR MEASURING CONDITIONS IN DEEP WELLS 5 Sheets-Sheet 4 Filed April 14, 1947 l INVENTOR. PHILIP W. MARTIN ATTO R N EY Aug- 19, 1952 P. w. MARTIN 2,607,220

MEANS FOR MEASURING CONDITIONS IN DEEP WELLS l Filed April 14, 1947 5 Sheets-Sheet 5 IZSN - INVENTOR. PHILIP w. MARTIN Q 'ATTORNEY L The .invention described;y s apparatusv operativen@ perforate;,thefeesinsget i a selected level., tousse-.off the.,eei r1s adiaeent the perforatons so asm toholdlback the-pressure fof: mud or otherv fluidqwhichimay be present in the casing andthereby permit ,entry offiuid from the adjacent formation 'ntothefinterier of the casing, and toqmemasure ordeterminefone or moreT a conditions, including pressure and temperature,

Furtherobjectsfand ad ntage .0f-the Speeicatien, wherein f -g-preferred 4.ermeediffrent @of :ill

'avten-teel ug.

'i 7 Claims.

My invention .relates to apparatus .tor Y measfuring conditions in wells,.and.is particularlyusefui for measuring. pressureiand/ or temperature. I HIt is an :object of .the inventiontoprovidea i measuring equipment, Whichvmay be lowered .into a well with oreindependently of. other equipment. gIt may be left in the Well .for along periodo-f time sol as to-measure changes in a value v:or

Y'values during such period-:offtime,;.onit maybe,

Elowered into a well withtestingfdevice,4 soL as `to make possible. the conducting'nf Lanumber 11 of. diierent tests yin .the Well and thetimmedate itransmission 1 of f information f, oro .-measures- ,re-

.ssultinge from-*these tests -.to the `,surfaoei these l:L ,informations or y measuresA being, :then utilized-in f determining operations whichV are to be per- 'fformed with yrelationto the well in ordergto ,obtain `foptimum. results onbest conditions ofA operation. For examplaitis possibleto make agnumbenof .itests' in the region Vofthe.leve1 {atwhichv an oil "tbody is known .to exist in order to maken, determivmations as to water entryvand-to transmit the :iresuits ofthese tests'mmediatelyto thebtopwof .ithe YWellk as the tests aresmade, therebyavoiding ithe, necessity of vvvithdravving theidevieffrom 'tine well after-'eachv test. I Ihe inventionlalso t imakes possible the determination of both pressure and temperature at different ltimesyand iunderV differentfconditions, these; values-being immediately utilizable in the; colpiti-'o1y of I further operations eonduotedywith respect. tothe Well. asmem ied I in :of the .fluid whieh has entered. the, easing, this information" b eing; .;ut.1zed;; 111.-; determining and-temperature to thveatop-of tn e yvelines tien may ibe: brought out 1nt YltQI: for the purpose of fully disclosing the same rettile-intenti@ is te pre- V- ;vide devine Qtthe that@eter-A Setfferth in the last preceding parasraphray having.: rnnlen Yet A efent elecilll'-meansgf0 IBfQSmQQQQQT- v-aymationA orindicatigns of'v the valu sgof pressure 1947;,u 'serial No; '141,212 (onta-151) fg Awithout limiting the invention dened ini the appendedciaims. .Referringto the drawings which are for illustrativepurposesonly; .t y. x 5 .i ,o Fia 11 .is a schematmviewvsnoi devceincluding alpreferred e invention' nv a .We1l,.casng.3wt`ll Q..Pilelfgi'f- Fia-aleen enlargedlosectional, View of the pberiportion .ofthe testing citeve.- 1o.. nig. s` .is `a,sectional yiew oi thats., ienooi `,tlfiemdevice immediately below the porti n shown i Figi. `4. s. a. sectional, View; of .tmatwportilonloi the device inunediately below the portion shown Eig,.-,5sis aisectionai vewaofdthe :device mmediatelylbeloviisthervporton shown in Fg i1 Fig. 6 is a partly sectioned view'of the lower end ofthedevice.. Yl FigJ is an enlargedsectionalview Qf. .the ,Dres- -sure responsive unit-.and associated parts dis.- clos'ed inthellowenporton 9 f E is. .Eig.8 is amiring diagram showing theelec -ical Lvequpment. employed iir 1 `,thepractice of the in- 25 vention hereinbeforeodescribedt, 9. is@a.diagramShowingh an Laltelijnative electrical.apparatuswhich may be used in the f praeticeof the invention, l L J Referring" to f P,ig. V,1, k:1 llave A shots/nfV a device 30E ineludingmy new linyentiellin e ,.,Geng f .10., .The device :T is suspendeldbyV vstringhof tubing Il which is threaded intoa, t formingfapart, o f.. tl1 e .device f1 yvni u .also a packer I3,I a reQetnll-Pimn a Per' forating sun 1,5-4, @sehe-W11 n* Fiss@ 'thead r I2V isfthreeged entame ure. mandrel I6 which extends axially thro'gl'ithe packer l3. A t;

irenlew i t s which are connected'by pins 3i' to ating 32 swivelly connected by a ring 33 with a sleeve 34 which carries bow springs 35 for frictionally engaging the inner surface of the casing l0. The lower end of the sleeve 33 is slidable on a tubular connector body 31 having threads 38 at its upper end, whereby it is connected to a sleeve 39 having threaded connection 40 with the lower end of the part 25. 'Ihe sleeve 39 has near its upper and lower ends openings 4| and 42, and defines around the mandrel I6 an annular cavity 43 containing a oylindric sleeve valve 54 containing packing 45 for closing radial ports fit in the lower portion of the mandrel IS. The sleeve 3d has a bayonet slot 41 therein which receives a projection on the connector body 31 consisting of the head of a screw 48 which threads into the body 31.

The lower end of the connector body 31 has threaded thereon a bushing 39 defining a downwardly faced cavity 55 which receives a threaded projection extending upwardly from a fitting 52 which is connected by a threaded connection 53 to the lower end of the mandrel l5. The projection 5| of the tting 52 has thereon a helical thread 5d of sawtooth form arranged to be engaged by the teeth or threads 55 of at least one body or slip 56 externally tapered so as to engage the inner tapered surface 51 of the bushing 59. The fitting 52 may be disengaged from the lower end of the connector member 31 by i rotation of the fitting 52 so that the thread 54 will feed down out of engagement with the teeth or threads 55 of the slip or block 55. This rotation of the tting 52 may be accomplished after the jaws 28 are set against the inner surface of the casing IG, by rotating the tubing which rotation is transmitted through the head |2 to the mandrel |5 and by the mandrel |6 to the fitting 52.

The fitting 52 has a downwardly extending projection 58 which, as seen in Fig. 5, is threaded so as to receive the upper end of a cylindric receiving unit housing 59 having openings 69 therein. The receiving unit Ill occupies the chamber 5| within the housing 59. The lower end of the housing 59 is closed by a fitting 62 joined to the lower end of the housing 59 by a threaded connection 63. The fitting 62 has a downwardly extending threaded projection 64 for receiving the upper connection 65 of the perforating gun I5, schematically indicated as being of the type having a plurality of gun barrels 65 which carry projectiles 51.

The fitting 65 at the upper end of the gun l5 has therein a chamber 54 in which the electrical iiring means 69 of the gun |5 is placed, this iiring means having at its upper end a contact 15 which engages an electrical conductor 15 shown as a screw. The details of the firing means 35 are not shown for the reason that such firing means may be any of the known types. It may be adapted to fire all of the powder charges of the gun simultaneously or consecutively. In one use of the invention, it may be desired to lire all of the projectiles at the same time, while in another use of the invention, consecutive ring is employed in conjunction with a plurality of tests made in different localities in the well without the necessity of removing the testing device from the well.

As shown in Fig. 5, the receiving unit Hl comprises a cylindrical metal shell '|1 having openings 18 near the upper end thereof. A plug 19 is fitted into the upper end of the cylindric shell 11, this plug 19 having an annular recess 83 covered by a flexible tubular wall 8| and communicating through openings 82 with a downwardly faced recess 33 in the plug 19. The lower end of the shell 11 is closed by a pressure responsive unit P having a cylindric shell 8&3, as shown in Fig. '1. The shell 811 has an upwardly faced recess 85 and a recess 86 of smaller diameter in the bottom of the recess 85. In the bottom of the recess 85 there is a circular insulator 31 supporting a U-shaped laminated iron core 88 having an inductance winding 83 on its legs. A plug 98 is threaded down into the recess 85. This plug 93 is in the form of an inverted cup and in turn has threaded upwardly thereinto a cup member 5|, the transverse wall of which forms a diaphragm 92 which closes an air chamber 93 in the upper part of the plug 93. The plug 9E has flow limiting openings 95 therein for connecting the interior of the shell 11 with the lower part of the recess 85 and with the interior of. the cup 9|, so that the pressure within the shell 1'i will be transmitted to the lower face of the diaphragm 92, thereby changing the space be tween the diaphragm 92 and the core 88 and thereby varying the inductance of the variable inductanoe L, which includes the core 88, the winding 89 and the armature formed by the diaphragm 32. The shell 83 has therein a passage 95 which connects the upper face of the shell 85 with the small recess 86 lying below the wall of insulating material 81.

Within the shell 11, between the plug 19 and the pressure responsive unit P, there is a condenser which is bridged across the inductance winding 89 as shown in Fig. 8, by use of electrical connections which will be hereinafter described. Also, in the shell 11 there is a condenser 96 which is bridged across the inductance winding 83 associated with a temperature responsive means T. This temperature responsive means T is disposed in a depression or recess 80' in the lower cylindrical wall portion of the plug 19 which closes the upper end of the shell 11. The temperature responsive means T has a part 94 which extends within the interior space defined by the lower portion of the plug 19 and supports an iron armature 92 in movable relation to the ends of the legs of a U-shaped core |38 on which the coil 39 is wound.

The winding 89 is connected by a conductor 51 with a screw |51 which, as will lbe hereinafter described, forms a portion of a conductor means H9 which extends to the top of the well to connect with oscillators O and O. A conductor |0| connects the lower terminal of the winding 89 with one terminal of the winding 83. Conductors 53a and SEZ) are employed to bridge the condenser 96 across the winding S9, and conductors S80 and 98d are employed to bridge the condenser 9G' across the winding 89. In this manner, resonant circuits C and C are formed. As shown in Fig. 7, one terminal of the winding 39 is connected to a terminal 99 which is in turn connected by a conductor I0 a with a screw |00. The screw l @il is connected to the conductor 95h.

All of the internal spaces of the receiving unit ld, with the exception of the air chamber 93, are filled with an insulating liquid such as transformer oil. This body of liquid engages the inner face of the flexible wall 8| and external pressures applied to the iiexible wall 8| are transmitted to the insulating liquid body, and through this liquid body, are transmitted to the lower face of the armature S2 to iiex the same away from the iron core 88 of the inductance L. The inductance lations in the circuit to which it is connected, or it may be cali-brated so as to directly indicate pressures to which the diaphragm 92 is exposed.

As shown in Figs. l and 8, there is at the upper end of the well an oscillation generator O which is similar in all respects to the oscillation generator O, with the exception that it is adapted to oscillate within a lower frequency range, and is connected to the conductor I I9 through a low pass filter 1|' instead of through the high pass filter 1I. In view of its similarity to the oscillation generator O, the oscillation generator O is not described in detail, but the elements thereof which have previously appeared in the oscillation generator O have -been indicated by the numerals employed in oscillation generator O with prime marks applied thereto. The oscillation generator O cooperates with the resonant circuit C which is tuned to respond to a lower frequency than the resonant circuit C. When the oscillation generator O is energized, as a result of the closing of its switch S', the resonant circuit C will be energized and will produce oscillations having a frequency determined by the position of the armature 92 which is controlled by the temperature responsive element T.

As schematically indicated in Fig. 8, the conductor means I9 is electrically connected through the windings 8S and 39 with the electrical ignition control means 69 of the gun I5. For actuation of the device, I provide at the top of the well a source of electrical current of sumciently high voltage and amperage, shown as a battery I3I, one terminal of which is connected through a conductor |32 with the ground conductor |23. A conductor |33 is extended from the conductor means H9 and by closing of a switch |34, this conductor |33 may be connected directly to the battery IBI, thereby applying to the circuit which extends into the Well a heavy current which will cause incandescence of the filament |2 and the ignition of the powder charge of the fuse i4. For testing the circuit extended into the well, a switch |35 may be closed so as to connect the conductor |33 with the battery through a resistor 35 and a meter |31. if the firing or ignition device G9 of the gun i5 includes a fuse in series with the conductor means Iil, the test made by the closing of the switch 535 will indicate whether or not this fuse has been ruptured.

Where the resonant circuits C and C are employed as shown in series with the gun firing device, and with each other, instead of in parallel,

the capacitor 9E of the low frequency resonant circuit C is provided with a capacitance of such large value that it will transmit or pass the high frequency wave corresponding to the frequency of the resonant circuit C, and the choke 89 of the high frequency resonant circuit C will be provided with such low inductance that it will pass the low frequency alternations corresponding to the low resonant frequency of the resonant circuit C. The high and low frequency oscillations from the oscillators O and O will pass through the circuit and electrical devicesv which are lowered into the well, but they will cause only the resonant circuits C and C of corresponding resonance to resonate. The high and low pass filters 1I and 1I guard the oscillators O and O against frequencies outside the frequency ranges in which they are designed to operate.

In one important use of the invention, the tester T is lowered down into the well casing I0 through the liquid content thereof by use of the tubing I I'. Periodically during the descent of the tester T, the cable |40 and the sinker |4I may be lowered through vthe tubing so as to connect the conductor of the cable |40 with the connectionA pin I5I. Vvhen this is done, test switch |35, Fig. 8, may be closed, and the meter |31 may be observed to determine whether the conducting means IIS is completely connected through electrical equipment of the testing device T. Also, the oscillation generators O and O may be selectively actuated so as to obtain readings of a liquid pressure and/or temperature at desired levels in the well. When the testing device T has been lowered so as to bring the perforating gun |5 to the level selected for `the testing operation, the cable |40 and the sinker I4I may be again lowered into the tubing to make connection with the connector pin |5I. Thereupon, the oscillation generators O and O may be actuated so as to determine the pressure and temperature existing at the level of the receiving unit I4.

After the foregoing information is obtained, the perforating gun I5 may be fired by closing the switch |34. If the oscillation generator O is in operation at the time the perforating gun is fired, the impulse applied to the diaphragm 92 of the pressure responsive means in the well will be indicated by a deflection of the pointer of the meter |24, thereby performing one of the valuable functions of the electrical equipment of the invention, that of definitely indicating at the top of the well the firing of the gun i5.

As soon as the gun is fired, the packer may be actuated. This actuation of the packer I3 is accomplished by rotating the upper end of the tubing I I so as to rotate the packer body |9 with relation to the sleeve 34 so as to carry the projection 48 into alignment with the Vertical portion of the bayonet slot 41. Whereupon the packer i body may be lowered so as to move the tapered guides 21 downward with relation to the jaws 28. thereby forcing the jaws 28 out against the casing. When the jaws 28 have been set, the tubing I I may be rotated so as to turn the mandrel I6 with relation to the packer body and screw the thread 54 of the tting 52 downward out of engagement with the member 5B. Then, the tubing I may be lowered so as to carry the head i2 downward within the perforate sleeve I1 into engagement with the seat I1' in the upper end of the upper portion 26 of the packer body. Sufficient of the weight of the ytubing may be applied to the parts 20 and 2| of the packer to shear the pin 25, whereupon the shoulder a of the member 20 may be moved downwardly with relation to the shoulder b at the upper end of the member 24, to compress the lpacking rings 22 axially and thereby expend them out into engagement with Ithe ilnner surface of the casing I0, as shown in Fig.

W hen the mandrel is moved downward, as explained in the foregoing, the ports 46 thereof will be displaced downward, as shown in Fig. 1, into a position below the valve 44, thereby opening the interior space of the mandrel I 6 to communication with the interior of the casing I0 below the packer, so that there may be a ow of fluid from the casing below the packer up through the mandrel I6 and through the passage |53 of the head I2 into the lower end of the tubing I I. This flow of fluid into the tubing I| reduces the uid pressure in the well casing below the packer I 3 and permits fluid to enter the casing from the surrounding formation, through the perforations p made by the passage of the .projectiIes |15 fired from .the perforating gunY I5, provided, ofcourse, that there is fluid Iunder pressure in -theadjacent formation. Ordinarily, the .next step in thepractice of the invention is toshutoll the flow from the upper endo-f the tubing I Iand :to then oper- .ate the oscillation generator Oso as to obtain -knowledge from the meterr |24 .thereof .and information .of the static formation pressure vap- This information may be Vas to make determinations as to the capacity of the formation. Pressure changes-resulting inthe space below the packer from changes in rate vof Aflow may be noted and compared with otherpres- `sure records obtained. .If the volume andthe pressure of the oil encountered in the adjacent formation are sufficient, a flow .of oil will be produced through the tubing I I, thereby bringing to the operator at the top of the well knowledge of the lluidcontent of the formation. If such'llow tlrirough the tubing is not accomplished, .pressure readings may be takenand a sample taken by raising thetubing II to shift the mandrel upward from the position thereof shown in Fig.Y 1 vtothe position thereofshownin Fig. 4.,.bringing thepolfts 46 of the mandrel I5 into the cylindric valve 4t` so as to close the lower end of a mandrel AI6 and trap within the mandrel,l and also within ,theA lower `part. of 'the tubingI I, a sample. offluid to be carried to the surfacefcr inspection.

Fig. 9 I show resonant circuits R and R of like characteristics adapted to be substituted vfor the resonant circuits C and C' of '.Fg. 8, these resonant circuits R and R respectively having Vvground and to conductor means II9b which extends from within the well to the. surface andfis connected through a condenser withan oscillationgenerator or single-ended oscillatorGof the type described in Fig. 8. The oscillation generator G isgrounded through a conductor |230.

and a direct current potential, shown as a batf `,tery |16,.is.connected across the ground. conductor |.23a and `the. conductor means IISb through apolarity reversing switch |11 and a chokecoil .|18 which will inhibit. passageV of oscillations from the oscillation generator .G through 4the battery |16 .toground The lower-end of the conductor means .I ISb is connected to the resonantcircuits R and R through valves shown as .rectifiers |80 and ISa positioned as shown. A frequency meter I8| is connected to the oscillation generator G, this frequency meter having a pointer v|32 which will swing in one direction 'from center, for example, ri-ghtward, in response .to a positive llow of current therethrough and which pointer will swing leftward from center in response to a negative .flow of current therethrough. The polarity reversing switch-|11 is shown as of drum type, having .a pair of substantially semi-.circular contacts |83 and |84 which may be continuously rotated around a commoncenter so as to periodically reverse the polarity of the direct current applied by the battery |16 to the circuit whichv includes the oscillation vgenerator G. When the positive polarity of the current .from .the battery |16 is 4applied through the conductor means |I9b, current .will

Hflow through the resonant circuitR and the resonant circuit R will be inactive. At this time, therefore, the frequency of oscillation of the circuit energized by the oscillation generator G will be'determined bythe frequency characteristics of the resonantcircuit R', and-fthe needle-orpointer |82 of the frequency meter'II will swingr to the right to a position indicating temperature in the well. '.When negative polarity of the battery. |16 is applied .to the conductor means Illlb,current will pass through the resonantcircuit yR.but not through the resonant 'circuit."R, and thee-needle or pointer. |82 of the'frequency meterf |8| will swing to the left to indicate. pressure in the wll.

VIf the circular contacts |83 and IBA-ofthefpolarity reversing switch I 11 are revolvda'roun'd their common center at a rate of.30 revolutions .per minute, the resonatorsR and' R willbelre- .therefore a. stylus carried by the.pointer.|82,

will inscribe on a moving record 30 pressure indications|92 .and 30 temperature indications'l93 per minute so that for all practicalpurposes, a substantially continuous record of pressureand temperature is obtained by use of'v a single Voscil lation generator G. It will be understoodthat the polarity reversing switch |11 maybe stopped in Vaposition to impresseither positive Ornegative .polarity `on the conductor means lIISb .so that atthis .time onlyoneof the measurements of temperature or Vpressurein thegportionof fthe well below thepacker I3 is obtained.

In certain periods, or-atcertain times .duri-ng the forming of a well, the well contains liquid.

,During .drilling operations, .for example, the -uncased hole and.4 also the cased portions of .thehole may .contain heavy drilling mud which exerts -Va staticv pressure to Vhold .back .fluids which .exist under pressure in the-formations. In-myrpresent invention Iprovide a method` and means whereby a portiontof the well is closedoff fromadjacen-t portions and a `path of flow for fluid is.estab.

lished from'the closed olf -portion to a Vzone of low pressure, Ifor example, the open atmosphere at the topof the well. In correlated or timed .relation thereto, tests of pressureand tempera'- ture,.or either fthem, as conditions mayreduire,

are made, .thereby giving the operator valuable information. 'The close-olf means,lfor example, .thepaoken holds the pressure. ofthefliquidin the well, for example, drilling. mud, water, oil,

.or mixtures thereof', off from -the closed-off .por-

'For example, the .measuring instruments which have their .pressure and 'temperature responsive elements exposed to conditions in the closed. off

lportion of the well are .placed in operation .at

a time prior to the operation o'f the'cl'o'se-off means so that the operatorat the topof the wll may take readings of pressure and. temperature existing in thedrilling mud or other liquidrwhich occupies the Well. Then, when thev fcl'os'efoi means ,is actuated, .the vcontinued measurements indicated by theapp'aratus jindicateth'attli same pressure and temperature may exist in the portion of the well below the close-oi means which existed prior to the operation of the closeoi means. When the path of ilow from the closeoff portion of the Well to the exterior is established, a drop in pressure in the closed oi portion of the well will be registered in timed relation to the establishment of the path of ow from the closed-off portion to the exterior, for the reason that fluid under pressure in the closed oi portion of the well passes into the path of flow provided by the tubing I l.

If there is no movement of iiuid under pressure into the closed oi portion of the Well, the pressure therein will drop to a characteristic value and remain there. But, if there is an entry of fluid from the adjacent formation into the closed off portion, the level of iiuid in the path of flow, represented by the tubing Il, will rise, and there will be an increase, or at times, abrupt increase in the pressure in the closed on? portion. and under some conditions, there will be a change in temperature in the closed 01T portion. If the pressure in the adjacent formation is sufficient, fluid will be caused to flow from the upper end of the tubing Il, and in order to obtain a measurement of the maximum pressure of which the adjacent formation is capable, the upper end of the tubing Il may be shut oiT or restricted, thereby making it possible to obtain a reading of the maximum formation pressure. However, if at the time the path of flow is established from the closed off portion to the top of the well, the inlet openings of such path of iiow should become clogged, as, for example, by drilling mud or materials from the formation, a drop in pressure in the closed off portion of the well will not occur, thereby indicating there has not been a release of pressure resulting from the establishment of the path of ow, and that interference to flow of fluid through the path of iiow has been encountered. This brings to the operator the knowledge that the high pressure then existing in the closed off portion is not representative of the formation characteristics. An important characteristic of the invention is that the pressure and temperature measurements are transmitted instantly to the top of the well so that the changes in these values, with relation to other acts are known to the operator at the times of their occurrence, thereby bringing to him knowledge of well conditions of dependable character. Also, it will be perceived that these valuable functions of the invention are obtainable independently of the perforating gun, since they involve only the use of the packer or other equivalent means for closing 01T a portion of the well and means for substantially instantaneously transmitting measurements of either or both pressure and temperature from the closed off portion of the well to the top of the well.

I claim as my invention:

1. In a device for measuring pressure and temperature in a well: a supporting member adapted to be lowered into the well; rst and second resonant circuits carried by said supporting member, each of said circuits comprising a capacitor and a variable inductor and said resonant circuits being tuned so as to operate in diilerent frequency bands; pressure responsive means arranged to vary the inductor of said first resonant circuit in accordance with changes in pressure to which said pressure responsive means is subjected; temperature responsive means arranged to vary the inductor of said second resonant circuit in accordance with changes in temperature to which said temperature responsive means is subjected; conductor means extending down into the well to said supporting member so as to form a transmission circuit means connected at its lower end to said iirst and second resonant circuit; means operative to supply electrical impulses to energize said resonant circuits and eifect oscillating current ows in said resonant circuits and said transmission circuit means, said oscillating current flows being varied by varying said inductors of said resonant circuits; filters at the top of the well tuned to said diiierent frequency bands; and indicating means at the top of the well connected respectively through said lters with said circuit means, said indicating means being responsive to said oscillating current flows to indicate respectively pressures and temperatures to which said pressure responsive means and said temperature responsive means are subjected in the well.

2. In a device for measuring pressure and temperature in a well: a supporting member adapted to be lowered into the well; rst and second resonant circuits carried by said supporting member, each of said circuits comprising a capacitor and a variable inductor and said resonant circuits being tuned so as to operate in different frequency bands; pressure responsive means arranged to vary the inductor of said first resonant circuit in accordance with changes in pressure to which said pressure responsive means is subjected; temperature responsive means arranged to vary the inductor of said second resonant circuit in accordance with changes in temperature to which said temperature responsive means is subjected; conductor means extending down into the well to said supporting member so as to form a transmission circuit means connected at its lower end to said rst and second resonant circuit; lters at the top of the well tuned to said different frequency bands; a pair of oscillation generators at the top of the well connected respectively through said filters with said circuit means, said generators energizing said resonant circuits and effecting oscillating current flows in said resonant circuits and said transmission circuit means, which oscillating current flows vary in accordance with the variation of said variable inductors; and indicating means at the top of the well connected respectively through said filters with said circuit means, said indicating means being responsive to said oscillating current flows to indicate respectively pressures and temperatures to which said pressure responsive means and said temperature responsive means are subjected in the well.

3. In a device for .measuring pressure and temperature in a well: a supporting member adapted to be lowered into the well; first and second resonant circuits carried by said supporting member, each of said circuits comprising a capacitor and a Variable inductor; pressure responsive means arranged to vary the inductor of said rst resonant circuit in accordance with changes in pressure to which said pressure responsive means is subjected; temperature responsive means arranged to vary the inductor of said second resonant circuit in accordance with changes in temperature to which said temperature responsive means is subjected; conductor means extending down into the well to said supporting member so as to form a transmission circuit means connected at its lower end to said rst and second resonant circuit;

13 means for polarizing said resonant circuits to opposite polarities; means operative to supply t oppositely polarized electrical impulses to energize said resonant circuits and eiect oscillating current flows in said resonant circuits and said transmission circuit means, said oscillating current flows being varied by varying said inductors of said resonant circuits; and indicating means at the top of the well connected through said circuit means with said first and second resonant circuits, said indicating means being responsive to said oscillating current ows to indicate respectively pressures and temperatures to which said pressure responsive means and said temperature responsive means are subjected in the well. y

4. In a device for measuring pressure and temperature in a well: a supporting member adapted to be lowered into the well; rst and second resonant circuits carried by said supporting membeneach of said circuits comprising a capacitor and a variable inductor; pressure responsive means arranged to vary the inductor of said rst resonant circuit in accordance with changes in pressure to which said pressure responsive means is subjected; temperature responsive means arranged to vary the inductor of said second resonant circuit in accordance with changes in temperature to which said temperature responsive means is subjected; conductor means extending down into the well to said supporting member so as to form a transmission circuit means connected at its lower end to said first and second resonant circuit; means for polarizing said resonant circuits to opposite polarities comprising oppositely faced rectiers connected respectively in series with said resonant circuits; means comprising an electrical pulsation generator and means operating to alternately apply to said transmission circuit direct current flows of opposite polarity operative to supply oppositely polarized electrical impulses to energize said resonant circuits and eiect oscillating current fiows in said resonant circuits and said transmission circuit means, said oscillating current flowsbeing varied by varying said inductors of said resonant circuits; and indicating means at the top of the Well connected through said circuit means with said rst and second resonant circuits, said indicating means being responsive to said oscillating current flows to indicate respectively pressures and temperatures to which said pressure responsive means and said temperature responsive means are subjected in the Well.

5. In a device for measuring a condition in a well: a supporting member adapted to be lowered into a well; a resonant circuit carried by said supporting member, said resonant circuit comprising a capacitor and a variable inductor; means acting in response to a condition in the well to vary said inductor in accordance with variations of said condition; conductor means extending down into the well from the top thereof to said resonant circuit and being connected therewith so as to form a transmission circuit; means operative to supply electrical impulses to energize said resonant circuit and effect oscillating current ilows in said resonant circuit and said transmission circuit, which oscillating current flows will vary in accordance with the variation of said inductor by said condition; and indicating means at the top of the well connected to the upper end of said transmission circuit,

said indicating means being adapted to respond to said oscillating current iiows and indicate the value thereof as a measure of said condition.

6. In a device for measuring a condition in a well: a supporting member adapted to be lowered into a well; a resonant circuit carried by said supporting member, said resonant circuit comprising a capacitor and a variable inductor; means acting in response to a condition in the well to vary said inductor in accordance with variations of said condition; conductor means extending down into the well from the top thereof to said resonant circuit and being connected therewith so as to form a transmission circuit; an oscillation generator at the top of the well connected to the upper end of said transmission circuit and being operative to supply electrical impulses to energize said resonant circuit and effect oscillating current iiows in said resonant circuit and said transmission circuit, which oscillating current flows will vary in accordance with the variation of said inductor by said condition; and indicating means at the top of the well connected to the upper end of said transmission circuit, said indicating means being adapted to respond to said oscillating current flows and indicate the value thereof as a measure of said condition.

7. In a device for measuring a condition in a Well: a supporting member adapted to be lowered into a well; a resonant circuit carried by said supporting member, said resonant circuit comprising a capacitor and a variable inductor; means acting in response to a condition in the Well to vary said inductor in accordance with variations of said condition; conductor means extending down into the well from the top thereof to said resonant circuit and being connected therewith so as to form a transmission circuit; an oscillation generator at the top of the well connected to the upper end of said transmission circuit and being operative to supply electrical impulses to energize said resonant circuit and eiect oscillating current iiows in said resonant circuit and said transmission circuit, which oscillating current ows will vary in accordance with the variation of said inductor by said condition; and the meter at the top of the Well connected in parallel with said oscillation generator and said transmission circuit, said meter responding to said oscillating current flows and indicating the value thereof as a measure of said condition.

PHILIP W. MARTIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,951,276 Edwards Mar. 13. 1934 2,190,260 Ennis Feb. 13, 1940 2,222,829 Humason et al. Nov. 26, 1940 2,245,700 Mounce June 17, 1941 2,280,785 Boynton Apr. 28, 1942 2,313,369 Spencer Mar. 9, 1943 2,330,509 McCullough Sept. 28, 1943 2,412,575 Frosch Dec. 17, 1946 2,421,423 Krasnow June 3, 1947 2,425,868 Dillon Aug. 19, 1947 2,441,894 Mennecier May 18, 1948 2,530,309 Martin Nov. 14, 1950 

